尖吻蝮蛇毒出血毒素DaHT-3的红外光谱测定  

Ft infrared Spectroscopic Determination of Hemorrhagic Toxin(DaHT 3) from Venom of Dienagkistrodon acutus

作　　者：叶文娟[1,2] 冉永禄[1,2] 赖仞 龚光林[1,2] 俞帆 曾昭权[1,2] 

机构地区：[1]中国科学院昆明动物研究所 [2]云南大学实验中心

出　　处：《蛇志》1999年第2期2-4,共3页Journal of Snake

基　　金：云南省自然科学基金

摘　　要：目的观察蛇毒出血毒素结构的变化对功能的影响。方法利用傅利叶变换红外光谱仪对尖吻蝮蛇毒出血毒素（ＤａＨＴ－３）在溶液中酰胺Ｉ带吸收光谱的研究，探测了此出血毒素在溶液中的自然构象和加入ＥＤＴＡ螯合剂除去金属离子后构象的变化。结果此出血毒素在水溶液中的自然构象分别是：α－螺旋为３１．８％、β－折叠为５６．１％、转角为１２．１％；而在去除金属离子情况下α－螺旋和β－折叠减少，转角和无规卷曲增加，即加入螯合剂后其α－螺旋、β－折叠、转角和无规卷曲分别变为１１％、２６．４％、４６．２％和１６．５％。由于结构的变化，它的出血活性和蛋白水解酶活性均被丧失。结论金属离子，特别是锌离子在维系蛇毒出血蛋白酶分子中的二级结构中起着很重要的作用。Objective The relationships between structure and function of purified hemorrhagic toxin(DaHT 3) from the venom of Dienagkistrodon acutus should be understood Methods The conformation of a novel hemorrhagic toxin was estimated by Fourier transform infrared(FT IR) spectrometer Absorbent bands of amide I in the both of natural status and metal ion status removed by EDTA were displayed Results The contents of secondary structure of DaHT 3 in aqueous solution were α helix of 31 8%,56 1% for β pleat sheet, and turn of 12 1%, respectively There was no unordered structure in the sample After the addition of EDTA, which moved metal inons, its FT infrared spectra were found to be very different The calculating result according to the spectra showed that the α helix,β pleat sheet, turn, and unordered structure were 11%, 26 4%, 46 2%, and 16 5%, respectively As indicated above, α helix and β pleat of DaHT 3 which removed metallic ions were decreased, while turn and unordered structure were increased Their hemorrhagic activity and proteolytic activity was lost when the conformation of the toxin was changed Conclusion It could be considered that metal ions, particularly Zn 2+ ion, played important role in maintaining secondary structure of the hemorrhagic toxins purified from snake venoms

关 键 词：尖吻蝮蛇毒 蛇毒 出血毒素 红外光谱 

分 类 号：R996.3[医药卫生—毒理学] R991[医药卫生—药学]